Mower-knife.



No. 795,550. PATENTED JULY 25, 1905.

. F. SCHUM.

MOWER KNIFE.

APPLIOATION FILED PEB. 2.1903.

@ www# UNITED sTATEs PATENT oEEIoE.

FRANK SCHUM, OF CHICAGO, ILLINOIS.

IVIOWER-KNIFE.

To all whom, it may concern.'

Be it known that I, FRANK SCHUM, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Mower-Knives; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention, such as will enable others skilled in the art to whichit appertains to make and use the same.

My invention relates to an improved knife for mowers and the like, theobject being to produce a knife which will be less expensive tomanufacture than the knife in use at the present time, which can be moreeasily sharpened, and which will tend to retain a sharp cutting edge asit wears in use; and it consists in the features of construction andcombinations of parts hereinafter fully described and claimed.

In the accompanying' drawings, illustrating my invention, Figure l is across-section of a cutter-bar of a mower provided with knives made inaccordance with my invention. Fig. 2 is a top plan view of a singleknife as illustrated in Fig. l. Fig. 3 is a sectional view of the knifeon the line 3 3 of Fig. 2. Fig. 4 is a broken horizon tal section, on areduced scale, on the line 4 4 of Fig. 1.

The ordinary construction of reciprocating cutter` for mowers, reapers,and similar harvesting-machines is to mount a plurality of triangularknives side by side on a bar which is adapted to be reciprocatedlongitudinally. The knives project forward of the bar and are providedon their angular lateral sides with suitable cutting edges. The knivespass through recesses in what are termed iingers, and their lower facesrest and shear on hardened steel plates, which are inserted in saidrecesses of said fingers. The ordinary knife is made by punching' therequired shape from sheet-steel and then grinding the upper sides of thelateral edges to a bevel to form the cutting edges. This latter step inthe process is slow and expensive. The ordinary knife is chilled in useby the edge wearing away on the lower face, which renders the latterconvex. The ordinary knife can be sharpened by grinding down the bevelededges; but the convex lower face cannot readily be ground, as this wouldreduce the thickness and render the knife too weak for further use. l

To overcome the above difliculties, I provide a knife A with flangedlateral edges B,

Specification of Letters Patent.

Application filed February 2, 1903. Serial No. 141,588.

Patented July 25, 1905;

which project below the body of the knife on a bevel and are ground ontheir lower faces parallel with the'plane of the body. Said edges B areadapted to rest on and coact with the shearing plates C, which arerigidly mounted in the fingers D.` Said fingers D project forward fromthe bar F beyond the path of said knives and are adapted to enter anddivide the material being cut as the cutters are advanced into same.Said bar F is adapted to carry the reciprocating cutter-bar G, on whichsaid knives A are rigidly mounted. The rear ends of said knives areadapted to rest on a shoulder H on said bar F in order to maintain saidknives in a horizontal position. A longitudinal groove I is provided insaid bar F to receive said cutter-bar G.

There are probably many ways in which the beveled flanges B might beproduced; but I prefer to produce them as follows: The knifeblank havingbeen punched as in the method of making the ordinary knife, I bend thelateral edges B downwardly at a suitable angle, preferably about thirtydegrees. I then grind away the lower edges of the flanges B parallelwith the body of the knife until I have produced cutting edges, as at J.This process of producing the knife is much simpler and cheaper than theprocess of producing the ordinary knife.

My knife as it wears will always remain in proper shearing contact withthe shearingplates on account of the hollowed under surface produced bythe iianged edges B, and as these edges wear on their lower faces theywill tend to preserve a sharp cutting edge. However, should the cuttingedge become dulled it can be sharpened readily and quickly by grindingback the lower faces of the flanged edges B or by grinding the upperbeveled sides of the cutting edges as in the method of sharpening theordinary knife.

I claim as my invention- 1. In a machine of the type set forth, thecombination with the fingers having cut-away portions, shearing-platesrigidly mounted on the fingers and extending liush with the wall formedby said cut-away portions, a bar having a portion of its upper face cutaway, said bar seating in said cut-away portions of the fingers andhaving its forward end abutting the wall formed by the cut-away portionsof the ngers, said bar extending above the shearing-plates, areciprocatory cutter-bar in said cut-away portion of the bar, knivesrigidly mounted on said cutter-bar, and having down.-

ivardly-turned cutting edges bearing on the said shearing-plates,therear ends of the knives extending beyond said cutter-bar and seating onsaid bar.

2. In a machine of the type set forth the in said bar and having itsupper surface in alinement with the upper surface of said irstnamed barand knives attached to said cutterbar and having Cutting edges extendingdown- Wardly and contacting with said shearingplates.

In testimony WhereofIaiX my signature in presence of two witnesses.

FRANK SCHUM. Witnesses:

RUDOLPH WM. LoTZ, E. F. WILSON.

